Vulcanus is the "Angel of Avarice", an angel who is stealing money from the Netherworld in order to send it to Celestia, in Disgaea 4: A Promise Unforgotten. Over 400 years ago, Valvatorez was a powerful demon who was feared as The Tyrant. It was at this time that Valvatorez first met Vulcanus, then known as Artina, during a vampire hunt. Failing to scare her, Valvatorez promised never to drink blood until he could scare her. Unfortunately, she is killed by her own nation for healing an enemy soldier and became an angel.
After her death, Artina continued to watch over the solider that she saved, but was unable to save him from falling into despair and madness. She was eventually found and recruited by Flonne to collect funds from the Netherworld, where she met Valvatorez again.